1. Field of the Invention
The present invention relates generally to the field of odor control. More specifically, the present invention relates to the vaporization of odor neutralizing products and the transfer of such vaporized products to malodorous areas for masking and elimination of malodors.
2. Related Art
Air pollution is of great concern to the modem world. Pollution of the air is characterized by offensive odors and/or toxic fumes that are a nuisance to humans living near or traveling through the polluted areas (both offensive odors and gases with other polluting or negative properties such as toxicity are hereinafter referred to as xe2x80x9cmalodorsxe2x80x9d). Unfortunately, air pollution is often the result of an activity deemed valuable to our modern world. Examples of valuable activities that produce malodors include sewage and wastewater treatment, chemical manufacturing, agricultural and livestock fanning, waste incineration, and petroleum refinement. Rather than completely eliminate these valuable endeavors, society has decided to simply control or regulate the malodors produced from many air polluting activities, thereby retaining the benefit from the activities while greatly reducing the negative effects upon human life.
Scrubbers and electrostatic precipitators have been used in many malodorous systems to control pollution released into the open air. Scrubbers and electrostatic precipitators achieve pollution control by removing odors and other polluting impurities from system exhaust gas streams. In a scrubber system, exhaust gasses containing odorous particles such as sulfides are introduced to a precipitant such as sulfuric acid. Introduction of the odorous particles to the precipitant causes the odorous particles to bond with the precipitant and form a solid precipitate. The solid precipitate particles fall from the exhaust gas to the floor of the scrubber where they may be easily removed. By causing the odorous particles to fall to the floor of the scrubber, malodors are removed from the exhaust gas stream.
Similarly, electrostatic precipitators remove liquid or solid pollution particles suspended in an exhaust gas by ionizing the suspended particles and subjecting the charged particles to an electrode. The ionized particles are attracted to the electrode, where they are captured and removed from the exhaust gas, thus removing the malodor from the exhaust gas stream.
Unfortunately, scrubbers and electrostatic precipitators are generally limited to industrial activities because they can not be used to control malodors that are not contained within an exhaust gas stream of a closed system. Examples of systems where malodors are not contained within an exhaust gas stream include sewage pits, garbage dumps, and pig farms. Furthermore, there are some industrial systems that produce malodorous exhaust gasses which are difficult for scrubbers and electrostatic precipitators to control because of ineffective precipitants or ionization techniques.
Another method of controlling malodors involves masking the malodor with a pleasant aromatic liquid or neutralizing the malodor with an enzyme or catalyst. One method which has been suggested uses a distribution system including at least one vapor delivery air duct having a longitudinal series of vapor release ports extending over and around an odor source such a sewage treatment tank or a garbage dump. A blower pumps a stream of vapor-laden air through the duct and out of the release ports. Deodorizing liquid product is pumped to the system through an atomizing nozzle or a copper tube having a plurality of holes which release minute droplets of the deodorizing liquid product into the air stream. The liquid product is vaporized to some extent by the impact of the air stream on the droplets. Liquid product that is not vaporized is lost as the droplets fall out of the air stream and through holes located in the air duct or distribution pipes. A typical problem with this type of system is that vaporization of the liquid product is highly inefficient. Testing has shown that, under the best of conditions, only about 28 percent of the liquid product sprayed out of the atomizing nozzle or copper tube is vaporized and used by the system. A considerable amount of the remaining liquid product is often blocked from exiting the air duct, and the inefficiency of the system is compounded because the accumulated liquid product in the duct obstructs air flow.
Another distribution system vaporizes liquid deodorizing product by bubbling air through the liquid product. This bubbling action causes a vapor to rise from the liquid product. The vapor rising from the liquid product is passed to the air duct where it is eventually delivered to the malodor area. Because the system does not utilize an atomizing nozzle, liquid product is not sprayed into the air duct and no collection of liquid product occurs within the air duct. Nevertheless, this system is not effective for several malodorous applications because the bubbling system does not readily vaporize a sufficient quantity of certain deodorizing products and consequently is incapable of delivering sufficient quantities of the deodorizing product to an odor source to overcome the malodor.
Still other systems are designed to deliver liquid deodorant mist to a malodor area by the use of many nozzles in a multiple cluster system. In these systems, each nozzle directly distributes a spray mist of the liquid deodorant product into the malodor source. An example of such a system has been employed in a 100 ton per hour asphalt plant in Grand Rapids, Mich. where multiple nozzles spray liquid deodorant directly into a pollution containing stack to control the odor emanating from the stack. These types of open air spray systems tend to be very inefficient because much of the liquid deodorant is lost as it falls to the ground and does not vaporize and mix with the malodor. Additionally, the multiple nozzles used in these systems are costly and difficult to maintain. There is a tendency for the nozzles in these systems to clog or plug and deliver inconsistent rates of product to the malodorous area.
Accordingly, it is a primary object of the present invention to overcome many of the above deficiencies by efficient vaporization of liquid deodorant products and delivery of such vaporized products to a malodorous area without significant loss of the liquid deodorant products.
Another object of the present invention is to efficiently vaporize a vast array of liquid deodorizing products for delivery to a wide range of odor producing areas.
It is another object of this invention to provide a deodorizing system that is simple to install, reliable, easy to operate and maintain and competitively priced.
A primary objective when utilizing odor neutralizing chemicals is to provide for complete mixing of the odor neutralizing chemicals with the malodors, thus forcing a chemical reaction between the malodors and the neutralizing chemicals. To accomplish this, the present invention efficiently vaporizes odor-neutralizing liquid deodorants and distributes the vaporized deodorants into malodorous areas where the vaporized deodorants are readily mixed with the malodors to neutralize the malodors or otherwise render them harmless.
The invention comprises an inlet channel, a vaporization chamber, an air blower, and distribution pipes. Fresh ambient air is drawn into the system and through the inlet channel by the air blower, thus creating a stream of air flowing through the system. The stream of air is directed to the vaporization chamber where an atomizing nozzle sprays atomized liquid product into the vaporization chamber. Within the vaporization chamber, the atomized liquid product is vaporized and becomes entrained in the air stream flowing through the chamber, making the air stream a xe2x80x9ctreatedxe2x80x9d air stream. The treated air stream then flows through distribution pipes to a plurality of vapor release ports which allow the treated air to be released into the malodorous area.
The atomizing nozzle includes a tip for spraying atomized liquid deodorant from the nozzle and into the air stream. The atomizing nozzle receives a stream of pressurized air from an air pump and a stream of liquid deodorant from a liquid reservoir. The liquid deodorant may either be pulled from the liquid reservoir under a vacuum created by the atomizing nozzle (e.g., a siphoning nozzle), or it may be pumped into the atomizing nozzle by means of a metering pump which delivers product to the atomizing nozzle at a precise rate. The force of the air being pushed through the nozzle by the air pump causes the liquid deodorant to be atomized as it exits the atomizing nozzle.
Release of the liquid deodorant from the atomizing nozzle results in a very fine mist of minute droplets generally in the approximate range of between 20 and 50 microns and even smaller. Air pressure to the atomizing nozzle may be increased or decreased to adjust the size of liquid deodorant particles leaving the nozzle. As the air pressure increases, the size of liquid deodorant particles decrease, and vice-versa. As the mist is injected into the vaporization chamber, it is believed that many of the minute droplets vaporize immediately, possibly due in part to a lower pressure upon the particles upon leaving the atomizing nozzle and entering the vaporization chamber.
The vaporization chamber includes a top, a bottom, and a sidewall, as well as a chamber inlet and outlet to allow the air stream to flow through the chamber. The size of the vaporization chamber will vary depending upon the required output of the siphoning or spray nozzle. Larger vaporization chambers will be required for treatment applications requiring a greater rate of liquid deodorant delivery to the malodorous area. It is believed that the liquid-in-gas dispersion formed within the vaporization chamber is such that many of the fine liquid particles of deodorizer product stay in suspension and readily evaporate, or xe2x80x9cvaporizexe2x80x9d, their state changing from a liquid to a gas. Most of the larger and heavier liquid particles coalesce, condense and collect on the vaporization chamber walls or fall to the vaporization chamber floor. This larger liquid particle separation may be enhanced by providing a change in direction of the air stream or by providing a vaporization chamber having a closed end, i.e., an end having no chamber inlet or outlet. The excess liquid deodorant collected on the vaporization chamber walls is returned by gravity to the liquid reservoir. To this end the vaporization chamber is generally sloped toward the liquid reservoir so that liquid deodorant flows down the walls of the vaporization chamber and into the liquid reservoir. Accordingly, a large percentage of un-vaporized liquid deodorant is removed from the air stream by the vaporization chamber and returned to the liquid reservoir for re-use, thus minimizing the loss of liquid deodorant downstream from the nozzle, and increasing the efficiency of the system.
After leaving the vaporization chamber, the treated air stream (i.e. untreated air and vaporized deodorant) is routed through air ducts to the air blower. The air blower not only draws untreated air through the system, but also forces the treated air through the distribution pipes. The distribution pipes carry the treated air to various vapor release ports which distribute the treated air into or around odor producing areas. The treated air contains sufficient vapors to overcome and/or neutralize existing offensive odors in the malodorous area.
Accordingly, the present invention provides for more efficient vaporization of liquid deodorants and more effective delivery of the deodorants in vapor form to malodorous areas without significant loss of the liquid deodorant.
Additionally, the present invention provides for vaporization of a wide range of liquid deodorants for delivery to various malodorous areas.
Furthermore, because of its relatively simple design, the present invention provides an air deodorizing system that is simple to install, reliable, easy to operate and maintain, and is competitively priced.